Dragging nodes

[jamesj@bert.cs.byu.edu (JAMES JEREMIAH WAYNE )]

     I am new to MCL, so this message may very well display my ignorance.  I
would like to represent an undirected graph in a window which is freely
alterable by the user.  That is, I would like to let the user add and delete
nodes and edges as well as drag the nodes around to suit his/her fancy and
trail any associated edges as a node is dragged.  This last is the problem.
MCL does not seem to have the functions I need to modify a button-dialog-item
sufficiently to behave in this manner, and while attempting to design a custom
dialog-item, I discovered that defpascal, which I need to write the definition
function, appears to be crippled.  It works fine when writing functions with
no parameters, but when I include even one parameter, the compiler complains
about its type.  Does anyone have any ideas on how I can get around these
problems, or possibly an entirely different approach to implementing this?

Thanks,

Jerry James
jamesj@bert.cs.byu.edu